package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> getListWithTree() {
        List<CategoryEntity> categoryEntities = getBaseMapper().selectList(null);
        List<CategoryEntity> root = categoryEntities.stream().filter((categoryEntity -> categoryEntity.getParentCid() == 0))//找出父级菜单
                .map(categoryEntity -> {
                    categoryEntity.setChildren(getChildren(categoryEntity,categoryEntities));
                    return categoryEntity;
                })
                .sorted((Comparator.comparingInt(c -> (c.getSort() == null ? 0 : c.getSort()))))//排序
                .collect(Collectors.toList());
        return root;
    }

    @Override
    public void removeMenus(List<Long> asList) {
        //todo 检测是否被其他引用
        getBaseMapper().deleteBatchIds(asList);
    }

    private List<CategoryEntity> getChildren(CategoryEntity root, List<CategoryEntity> categoryEntities) {

        List<CategoryEntity> collect = categoryEntities.stream().filter(categoryEntity -> root.getCatId().equals(categoryEntity.getParentCid()) )
                .map(categoryEntity -> {
                    categoryEntity.setChildren(getChildren(categoryEntity,categoryEntities));
                    return categoryEntity;
                })
                .sorted((Comparator.comparingInt(c -> (c.getSort() == null ? 0 : c.getSort()))))//排序
                .collect(Collectors.toList());
        return collect;
    }

}